If mildew is already present on a substrate, the mildew but be killed and
removed before the substrate is finished, or else the mildew will grow through
the new coating. To kill mildew and remove mildew from the surface, follow the
steps outlined below:

1. Using a spray canister (one designed for insecticide application will do)
available at most hardware stores, apply the following solution liberally to the
substrate and allow to set for about 10-15 minutes:

a. 3 quarts water

b. One quart common household bleach

c. 1/4 cup maximum of liquid dishwasher detergent (*ammonia-free)

-you can also use powder detergent.

*Safety Tip:

*Do not use a detergent that contains ammonia; ammonia reacts with bleach to
form a poisonous gas. Many liquid detergents may contain other additives that
react with chlorine- containing bleach.

The bleach is the key component that actually kills the mildew. Allowing this
solution to set gives the bleach time to settle into any crevices and hard to
reach place to kill all the mildew present. Skipping this 10-15 minute set time
may result in an inadequate job. The detergent is added in a small amount to
help emulsify any mildew or dirt to aid in its removal. Liquid dishwasher
detergent is the best choice it will not foam like regular dish or laundry
detergent.

2. Using the same solution, wash the substrate clean using a power washer. A
Second choice if a power washer is unavailable is to scrub the surface with the
same solution. For wood, use a softer bristle brush. For anything sensitive to
abrasive damage like aluminum and vinyl siding, use a sponge.

Note:

If mildew was present on the original substrate or previous coats, and a new
finish coat is already applied, the mildew will grow through the coating. It is
usually impossible to stop mildew growth at this point. All the coatings must be
stripped down to the original substrate and then cleaned as described above
before applied a new coat. Paint strippers will remove oil-based stains and
latex stains. Most are supplied as ready-to-use liquids. Read the
manufacturer directions! After use, residual stripper should be thoroughly
rinsed from the wood surface before any other coating is applied.